The present invention mainly relates to resilient return means having a fixing seat, and to an elongate body fitted with such resilient return means.
The manufacturing of elongate tubular bodies fitted with an inner spring exerting an axial return force is well known. The seat of a spring of a known type bears on an inner shoulder of the elongate tubular body or on a retaining ring, received in a groove made in the radially-inner wall of the elongate tubular body.
The implementation of a shoulder means causes a considerable increase in the cost price of the spring-accommodating tubular body, whereas the use of a retaining ring implies a greater number of parts in the assembly, which leads to a more complicated manufacturing process. Besides, the shoulder or the retaining ring alters the hydrodynamic behaviour of the tubular body, which can turn out to be quite troublesome.
Therefore, it is an object of the present invention to provide resilient return means, more particularly a spring capable of seating on at least one wall of an axial or a substantially axial passage, made in an elongate element, so as to exert an axial or a substantially axial return force in said passage.
It is another object of this invention to provide resilient return means having a simple construction.
Another object of the present invention consists in providing such resilient return means, both reliable and having a long service life.
It is also an object of the present invention to provide an elongate body including an axial or a substantially axial passage fitted with axial or substantially axial resilient return means.
Another object still of the invention consists in providing such an elongate body fitted with said reliable resilient return means, at a moderate cost price while minimizing the hydrodynamic disturbances.
It is another object of the invention to provide a brake master cylinder, more particularly a tandem master cylinder, reliable, with a simple construction and at a moderate cost price.
These objects are achieved by resilient return means, more particularly a spring in accordance with the present invention, comprising a seat capable of fitting into a receiving cavity, made in at least one wall of an elongate element, typically in the radially-inner face of a wall of a tubular element, of a sleeve or similar.
This invention essentially concerns resilient return means, comprising an axial return element and an attachment seat, characterised in that the seat is radially compliant so as to be capable of elastically engaging with a receiving cavity, made in at least one wall of an elongate element.
Another subject matter of the present invention is resilient return means, characterised in that said means comprise a spring.
Another aspect of the present invention lies in resilient return means, characterised in that said spring is a spiral spring.
According to another feature, said resilient return means are characterised in that said spring is subjected to a compressive load.
The present invention also deals with resilient return means, characterised in that they comprise a polygonal seat.
Another subject of this invention is resilient return means, characterised in that the return element bears on the seat at three points of contact.
Another subject matter still of the present invention is an elongate body, comprising a passage fitted with a return spring, characterised in that said spring includes a resilient element and a radially-compliant seat capable of engaging with a receiving cavity, made in the inner wall of the passage provided in the elongate body.
This invention also deals with an elongate body, characterised in that said elongate body is a tubular one.
According to another aspect of the invention, such an elongate body is characterised in that the passage is rectilinear and in that the resilient return means are axially arranged in said passage.
In a further aspect of the present invention, such an elongate body is characterised in that said body is a tandem master cylinder and in that the resilient return means ensure the axial return of a valve.
Other features and advantages of the will emerge cllearly from the description thereof when taken in conjunction with the accompanying drawings.